Ahmed, G. Aggez U.

Aktas, Ö.

Al Aqueel, M.

Alayed, B.

Albers, H. M.

Algora, A.

Alhomaidhi, S.

Appleton, C.

Arici, T.

Armstrong, M.

Arnswald, K.

Balogh, M.

Banerjee, A.

Benito Garcia, J.

Benzoni, G.

Blazhev, A.

Bottoni, S.

Boutachkov, P.

Bracco, A.

Bruce, A.

Bruno, C.

Camera, F.

Cederwall, B.

Chishti, M. M. R.

Cortés, M. L.

Cox, D. M.

Crespi, F. C. L.

Das, B.

Davinson, T.

De Angelis, G.

Dickel, T.

Doncel, M.

Donthi, R.

Ertoprak, A.

Escudeiro, R.

Esmaylzadeh, A.

Fraile, L. M.

Gaffney, L.

Gamba, E. R.

Genna, D.

Gerl, J.

Gottardo, A.

Górska, M.

Ha, J.

Haettner, E.

Hall, O.

Heggen, H.

Hrabar, Y.

Hubbard, N.

Jazrawi, S.

John, P. R.

Jolie, J.

Jones, C.

Joss, D.

Judson, D.

Kahl, D.

Karayonchev, V.

Kazantseva, E.

Kern, R.

Knafla, L.

Kojouharov, I.

Korgul, A.

Korten, W.

Koseoglou, P.

Kosir, G.

Kostyleva, D.

Kurtukian-Nieto, T.

Kurz, N.

Kuzminchuk, N.

Labiche, M.

Lenzi, S.

Leoni, S.

Llanos-Expósito, M.

Lozeva, R.

Mengoni, D.

Mertzimekis, T. J.

Mikolajczuk, M.

Million, B.

Mistry, A. K.

Morales, A.

Mukha, I.

Murias, J. R.

Napoli, D.

Nara Singh, B. S.

O'Donnell, D.

Orrigo, S. E. A.

Page, R.

Pellumaj, J.

Pelonis, S.

Petrovic, J.

Pietralla, N.

Pietri, S.

Pigliapoco, S.

Podolyak, Zs.

Polettini, M.

Porzio, C.

Quintana Arnes, B.

Recchia, F.

Regan, P. H.

Reiter, P.

English

The HISPEC-DESPEC collaboration aims at investigating the structureof exotic nuclei formed in fragmentation reactions with decay spectroscopymeasurements, as part of the FAIR Phase-0 campaign at GSI. This paper reportson first results of an experiment performed in spring 2021, with a focus on β-decay studies in the Po-Fr nuclei in the 220 &lt; A &lt; 230 island of octupole deformation exploiting the DESPEC setup. Ion-beta correlations and fast-timing techniques are being employed, giving an insight into this difficult-to-reach region

Valiente-Dobón, J. J.

Zhang, G.

Vidal, R. M. Perez

Research Repository and Portal - University of the West of Scotland

 UWS Academic PortalDecay studies in the A  225 Po-Fr region from the DESPEC campaign at GSI in 2021Polettini, M.; Pellumaj, J.; Benzoni, G.; Valiente-Dobón, J. J.; Zhang, G.; Mengoni, D.; Vidal,R. M. Perez; Genna, D.; Bracco, A.; Ahmed, G. Aggez U.; Aktas, Ö.; Al Aqueel, M.; Alayed,B.; Albers, H. M.; Algora, A.; Alhomaidhi, S.; Appleton, C.; Arici, T.; Armstrong, M.; Arnswald,K.; Balogh, M.; Banerjee, A.; Benito Garcia, J.; Blazhev, A.; Bottoni, S.; Boutachkov, P.;Bruce, A.; Bruno, C.; Camera, F.; Cederwall, B.; Chishti, M. M. R.; Cortés, M. L.; Cox, D. M.;Crespi, F. C. L.; Das, B.; Davinson, T.; De Angelis, G.; Dickel, T.; Doncel, M.; Donthi, R.;Ertoprak, A.; Escudeiro, R.; Esmaylzadeh, A.; Fraile, L. M.; Gaffney, L.; Gamba, E. R.; Gerl,J.; Górska, M.; Gottardo, A.; Ha, J.Published in:Il Nuovo Cimento C  -Colloquia on PhysicsDOI:10.1393/ncc/i2022-22125-5Published: 31/10/2022Document VersionPublisher's PDF, also known as Version of recordLink to publication on the UWS Academic PortalCitation for published version (APA):Polettini, M., Pellumaj, J., Benzoni, G., Valiente-Dobón, J. J., Zhang, G., Mengoni, D., Vidal, R. M. P., Genna,D., Bracco, A., Ahmed, G. A. U., Aktas, Ö., Al Aqueel, M., Alayed, B., Albers, H. M., Algora, A., Alhomaidhi, S.,Appleton, C., Arici, T., Armstrong, M., ... Zyriliou, A. (2022). Decay studies in the A  225 Po-Fr region from theDESPEC campaign at GSI in 2021. Il Nuovo Cimento C -Colloquia on Physics, 45(5), [125].https://doi.org/10.1393/ncc/i2022-22125-5General rightsCopyright and moral rights for the publications made accessible in the UWS Academic Portal are retained by the authors and/or othercopyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated withthese rights.Take down policyIf you believe that this document breaches copyright please contact pure@uws.ac.uk providing details, and we will remove access to thework immediately and investigate your claim.DOI 10.1393/ncc/i2022-22125-5Communications: SIF Congress 2021IL NUOVO CIMENTO 45 C (2022) 125Decay studies in the A ∼ 225 Po-Fr region from the DESPECcampaign at GSI in 2021M. Polettini(1)(∗), J. Pellumaj(2)(3), G. Benzoni(1), J. J. Valiente-Dobón(3),G. Zhang(4), D. Mengoni(4), R. M. Perez Vidal(3), D. Genna(1), A. Bracco(1),G. Aggez(5), U. Ahmed(6), Ö. Aktas(7), M. Al Aqueel(8), B. Alayed(9),H. M. Albers(10), A. Algora(11), S. Alhomaidhi(10)(6), C. Appleton(12),T. Arici(5), M. Armstrong(13), K. Arnswald(13), M. Balogh(3),A. Banerjee(10), J. Benito Garćıa(14), A. Blazhev(13), S. Bottoni(1),P. Boutachkov(10), A. Bruce(15), C. Bruno(12), F. Camera(1),B. Cederwall(7), M. M. R. Chishti(16), M. L. Cortés(6), D. M. Cox(17),F. C. L. Crespi(1), B. Das(7), T. Davinson(12), G. De Angelis(3),T. Dickel(10), M. Doncel(18), R. Donthi(19), A. Ertoprak(3), R. Escudeiro(4),A. Esmaylzadeh(13), L. M. Fraile(14), L. Gaffney(9), E. R. Gamba(1),J. Gerl(10), M. Górska(10), A. Gottardo(3), J. Ha(4), E. Haettner(10),O. Hall(12), H. Heggen(10), Y. Hrabar(17), N. Hubbard(10)(6),S. Jazrawi(16)(20), P. R. John(6), J. Jolie(13), C. Jones(15), D. Joss(9),D. Judson(9), D. Kahl(21), V. Karayonchev(13), E. Kazantseva(10),R. Kern(6), L. Knafla(13), I. Kojouharov(10), A. Korgul(22), W. Korten(23),P. Koseoglou(6), G. Kosir(24), D. Kostyleva(10), T. Kurtukian-Nieto(25),N. Kurz(10), N. Kuzminchuk(10), M. Labiche(26), S. Lenzi(4), S. Leoni(1),M. Llanos Expósito(14), R. Lozeva(27), T. J. Mertzimekis(28),M. Mikolajczuk(22), B. Million(1), A. K. Mistry(10)(6), A. Morales(11),I. Mukha(10), J. R. Murias(14), D. Napoli(4), B. S. Nara Singh(29),D. O’Donnell(29), S. E. A. Orrigo(11), R. Page(9), S. Pelonis(28),J. Petrovic(7), N. Pietralla(6), S. Pietri(10), S. Pigliapoco(4),Zs. Podolyak(16), C. Porzio(1), B. Quintana Arnes(30), F. Recchia(4),P. H. Regan(16)(20), J.-M. Régis(13), P. Reiter(13), K. Rezynkina(4),P. Roy(31)(10), M. Rudigier(6), P. Ruotsalainen(32), E. Sahin(10)(6),L. G. Sarmiento(17), M.-M. Satrazani(9), H. Schaffner(10),C. Scheidenberger(10), L. Sexton(12), A. Sharma(33), J. Smallcombe(9),P.-A. Söderström(21), A. Sood(7), P. Vasileiou(28), J. Vesic(24),J. Vilhena(34), L. Waring(9), H. Weick(10), V. Werner(6),J. Wiederhold(6), O. Wieland(1), K. Wimmer(10), H. J. Wollersheim(10),P. Woods(12), A. Yaneva(13), I. Zanon(2)(3), J. Zhao(10),R. Zidarova(6), S. Ziliani(1), G. Zimba(32) and A. Zyriliou(28)(1) Dipartimento di Fisica, Università degli Studi di Milano and INFN Milano - Milan, Italy(2) Dipartimento di Fisica e Scienze della Terra, Università di Ferrara - Ferrara, Italy(3) INFN, Laboratori Nazionali di Legnaro - Legnaro, Italy(4) Dipartimento di Fisica e Astronomia, Università di Padova and INFN Padova - Padua,Italy(∗) On behalf of the HISPEC-DESPEC Collaboration.Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0) 12 M. POLETTINI et al.(5) Istanbul University, Graduate School of Sciences, Department of Physics - Istanbul,Turkey(6) Institut für Kernphysik, Technische Universität Darmstadt - Darmstadt, Germany(7) KTH Royal Institute of Technology - Stockholm, Sweden(8) Imam Mohammad Ibn Saud Islamic University - Riyadh, Saudi Arabia(9) Department of Physics, Oliver Lodge Laboratory, University of Liverpool - Liverpool, UK(10) GSI Helmholtzzentrum für Schwerionenforschung GmbH - Darmstadt, Germany(11) Instituto de Fisica Corpuscular, CSIC-Universidad de Valencia - Valencia, Spain(12) University of Edinburgh, School of Physics and Astronomy - Edinburgh, UK(13) Institut für Kernphysik der Universität zu Köln - Köln, Germany(14) Grupo de F́ısica Nuclear and IPARCOS, Universidad Complutense de Madrid - Madrid,Spain(15) School of Computing Engineering and Mathematics, University of BrightonBrighton, UK(16) Department of Physics, University of Surrey - Guildford, UK(17) Department of Physics, Lund University - Lund, Sweden(18) Department of Physics, University of Stockholm - Stockholm, Sweden(19) Department of Nuclear and Atomic Physics, Tata Institute of Fundamental ResearchMumbai, India(20) National Physical Laboratory - Teddington, UK(21) ELI-NP Center for Extreme Light Infrastructure, Nuclear Physics - Magurele, Romania(22) Department of Physics, University of Warsaw - Warsaw, Poland(23) Irfu, CEA, Université Paris-Saclay - Paris-Saclay, France(24) Jozef Stefan Institute - Ljubljana, Slovenia(25) CENBG, Université de Bordeaux, CNRS/IN2P3 - Bordeaux, France(26) STFC, Daresbury Laboratory - Daresbury, UK(27) Université Paris-Saclay, IJCLab, CNRS/IN2P3 - Paris-Saclay, France(28) National and Kapodistrian University of Athens - Athens, Greece(29) School of Computing, Engineering and Physical Sciences, University of West ScotlandGlasgow, UK(30) Laboratorio de Radiaciones Ionizantes, Universidad de Salamanca - Salamanca, Spain(31) Variable Energy Cyclotron Centre - 1/AF Bidhan Nagar, Kolkata, India(32) University of Jyväskylä - Jyväskylä, Finland(33) Department of Physics, Indian Institute of Technology Ropar - Ropar, India(34) LPMCN, Université de Lyon - Lyon, Francereceived 1 February 2022Summary.— The HISPEC-DESPEC collaboration aims at investigating the struc-ture of exotic nuclei formed in fragmentation reactions with decay spectroscopymeasurements, as part of the FAIR Phase-0 campaign at GSI. This paper reportson first results of an experiment performed in spring 2021, with a focus on β-decaystudies in the Po-Fr nuclei in the 220 < A < 230 island of octupole deformationexploiting the DESPEC setup. Ion-beta correlations and fast-timing techniques arebeing employed, giving an insight into this difficult-to-reach region.DECAY STUDIES IN THE A∼225 Po-Fr REGION ETC. 31. – IntroductionOctupole correlations are the result of the long range octupole-octupole interactionbetween nucleons occupying pairs of orbitals which differ by 3 units in both orbital andtotal-angular momentum. This results in asymmetric shapes, also known as pear-likeshapes [1]. These exotically-deformed nuclei can be found in selected areas of the nuclearchart, in particular in the mass regions A  146 (Xe-Sm region) and A  222 (Rn-Thregion), called islands of octupole deformation [2]. To find direct experimental evidenceof these elusive shapes proves to be very challenging, and it is worth exploring severalspectroscopic properties in a wide range of nuclei. The first signature is the excitationenergy spectrum itself, characterised by alternating, almost degenerate, negative- andpositive-parity states. Octupole deformation also results in large E3 and E1 strengthsdue to the separation of the centre of mass and the centre of charge in the nucleus [3].Atoms whose nucleus displays static octupole deformation can be an ideal laboratoryfor measurements of electric dipole moments [4]. The Rn-Th isomers with A  222are expected to show the largest octupole deformations, as highlighted both by recentexperimental measurements [5, 6] and by theoretical calculations [7, 8]. Our experimentwas focused on two main aims: finding evidence of octupole deformation in the nucleiof interest populated via β decay and providing new β-decay data to test r-processnucleosynthesis models.2. – Experimental setupThe experiment described here was performed at the GSI-FAIR facility in Darmstadt,Germany, in April 2021, within the experimental program of DESPEC Phase-0. The cam-paign focused on investigating the inner structure of exotic nuclei formed in high-energyprojectile-fragmentation reactions. The nuclei of interest were produced in fragmentationreactions of a primary beam of 238U on a 9Be target. The primary beam had an intensityof ∼109 /s and a spill length of 4 s. The fragments composing the secondary beam wereselected using the FRagment Separator (FRS) [9] with the Bρ−ΔE − Bρ method andidentified using the TOF−Bρ−ΔE method [10], collecting information on the ions’ timeof flight, position in the focal planes, and atomic number Z. The ions of interest werethen transported towards the DEcay SPECtroscopy (DESPEC) station [11], where theywere implanted into the AIDA (Advanced Implantation Detector Array) stack of threedouble-sided silicon-strip detectors (DSSDs) [12]. This active stopper is sandwiched be-tween two plastic detectors made of tiles of BC-400 scintillator material, read out by 16series of SiPM coupled to each side. The plastic detector is used for timing measurementsof the β particle emitted in the decay. The decay station also comprises a hybrid array ofHPGe and LaBr3(Ce) detectors to measure the γ rays emitted in the de-excitation of thedaughter nuclei. The FATIMA (FAst TIMing Array) consists of 36 LaBr3(Ce) detectorswith a full-energy peak efficiency of 2.9% at ∼1MeV [13, 14]. An array of four 7-foldEUROBALL HPGe clusters [15] in forward position is used for precision γ-ray energymeasurements, with an efficiency of 2% at ∼1MeV. Independent data acquisitions ofthe subsystems were synchronised with a time sorter using a distributed clock.3. – Study of the implantation profile in AIDAThe initial stages of the data analysis were focused on the identification of the ionsof interest and the study of their implantation profile. The Particle IDentification (PID)plot, reported in fig. 1, shows the ions of interest in terms of their reconstructed Zand A/Q ratio: 228,229,230Fr, 226,227,228,229Rn, 224,225At, together with several other ion4 M. POLETTINI et al.Fig. 1. – Left: particle identification plot obtained for our dataset. Middle (right): implantationprofile of francium (astatine) isotopes in the three AIDA detectors.species that can be investigated with this measurement. A study of the implantationprofile in AIDA was performed by evaluating the depth reached by the nucleus withinAIDA layers, as shown in the middle and right panels of fig. 1 for Fr and At isotopes,respectively. Ions with different atomic number Z have a different implantation profile,which will be of help in the study of ion−β correlations. Ad-hoc correlation algorithmsare being developed in order to perform ion-β and ion- β − γ − γ correlations. Thisanalysis will be used to study the inner structure of the daughter nuclei by identifyingnew decay transitions and evaluate the presence of octupole deformation.4. – ConclusionsThis paper reports on the study of the implantation profile in an experiment performedat GSI in April 2021 within the DESPEC-Phase 0 campaign framework. The studypresented here is focused on the investigation of the presence of octupole deformation inPo-Fr nuclei in the A∼225 island of octupole deformation.∗ ∗ ∗The authors acknowledge the GSI accelerator team and the FRS group. Support byINFN, the BMBF and the UK Science and Technology Facilities Council is acknowledged.REFERENCES[1] Butler P. A., Phys. G: Nucl. Part. Phys., 43 (2016) 073002.[2] Carpenter M. P., J. Phys.: Conf. Ser, 312 (2011) 092006.[3] Butler P. A., Proc. R. Soc. A, 476 (2020) 0202.[4] Chupp T. E., Rev. Mod. Phys., 91 (2019) 015001.[5] Gaffney L. P. et al., Nature, 497 (2013) 199.[6] Chishti M. M. R. et al., Nat. Phys., 16 (2020) 853.[7] Robledo L. M. and Butler P. A., Phys. Rev. C, 88 (2013) 051302(R).[8] Xia S. Y. et al., Phys. Rev. C, 96 (2017) 054303.[9] Geissel H. et al., Nucl. Instrum. Methods Phys. Res. B, 70 (1992) 286.[10] Münzenberg G., Nucl. Instrum. Methods Phys. Res. B, 70 (1992) 265.[11] Mistry A. K. et al., Nucl. Instrum. Methods Phys. Res. A, 1033 (2022) 166662.[12] AIDA, Technical report (2008).[13] FATIMA, Technical report (2015).[14] Rudigier M. et al., Nucl. Instrum. Methods Phys. Res. A, 969 (2020) 163967.[15] Beck F., Prog. Part. Nucl. Phys., 28 (1992) 443.

Decay studies in the A ∼ 225 Po-Fr region from the DESPEC campaign at GSI in 2021

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Decay studies in the A ∼ 225 Po-Fr region from the DESPEC campaign at GSI in 2021

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